Synthesis and characterization of Zr and Mg doped BiFeO3 nanocrystalline multiferroics via micro emulsion route

Abstract BiFe 1–2x Zr x Mg x O 3 (x = 0.00, 0.05, 0.1, 0.15, 0.2 and 0.25) nano-sized multiferroics were synthesized by micro emulsion technique. The structure analysis, thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), magnetic measurements and dielectric properties were studied for prepared samples. Differential scanning calorimetry (DSC) and differential thermogravimetric analysis (DTA) confirm multiferroic characteristics of the samples. DTA curve indicates the presence of ferroelectric transition temperature at 806.79 °C. XRD results indicated that crystallite size is found in the range of (22.5–18.00) nm and other parameters like bulk density, X-ray density and porosity were also measured from the XRD data and were greatly influenced by increasing the dopants concentration. FTIR spectra revealed that the characteristics bonds of BiFeO 3 are appreciably influenced by Zr–Mg contents. Magnetic analysis reveals that saturation magnetization (Ms) and remanent (Mr) increase with Zr–Mg doping because magnetic moment of Zr 4+ is zero and doping of Zr 4+ at Fe 3+ site increase align spin but Mg 2+ doping in BiFeO 3 increases saturation magnetization not too much as compared to other alkaline earth metal ions because Mg 2+ contain smallest ionic radius among alkaline earth metals. Ms reaches maximum value of 0.979 emu/g for composition x = 0.25. Multiferroics BiFe 1–2x Zr x Mg x O 3 are useful for ferroelectric random access memories (FeRAM) where data can be written electrically and read magnetically. It is found that all dielectric parameters strongly dependent on Zr–Mg contents. At higher concentrations, complicated dielectric behavior is observed. Dielectric results exhibited that dielectric parameters decrease with increase in frequency in the range of 1 MHz–3 GHz suggest that these multiferroics are useful for high resonant circuits.